M5A1 U.S. Light
Tank :
The light tank M3 entered production in the Spring of 1940 and in the
next three years, many thousands of vehicles of this type were built in
several different production forms. The M3 was designed around the
continental W-670 seven cylinder gasoline engine, and it became apparent
very early on that supply of this engine would be subject to
restrictions because it was adapted aero engine and the expanding aircraft
production lines would have priority call on essential components and
facilities. One model of the Light Tank M3 was fitted with a diesel engine
to help overcome the shortages, but a better idea came from the Cadillac
Division of General Motors who were already engaged on war work. Cadillac
suggested to the US Ordnance Department that it would be possible to fit
two of their existing big V-8 motor car engines, together with the
associated Hydramatic transmission systems, into the existing M3 Light
Tank. To prove the feasibility of this, one standard M3 vehicle was
converted (under the experimental designation M3E2) for official
trials. A 500 mile continuous trial run was made, absolutely free of
faults or mechanical trouble. late in 1941. On test the vehicle proved
mush easier to drive and handle than the original Continental engined
vehicles, and the legendary Cadillac smoothness of operation seemed to
lend itself as well to tanks as to luxury motor cars.
The modified design was approved for production straight away, and the new
type was standardized as Light Tank M5 (not M4, so as to avoid confusion
with the Medium Tank M4).
To
accommodate the height of the twin Cadillac engines the rear decking of
the hull was slapped up, but the hull was otherwise quite similar in shape
to that of the original M3. One change, however, was to a sloping glacis
plate. Production started in February 1942. Two Cadillac plants was
building M5s by the summer of 1942, plus a Massey-Harris Factory, and in
October 1943 M3 production ceased and the M3 builder, American Car & Foundry,
switched to M5 production as well. In September 1942 a slightly improved
model, M5A1 was standardized to bring the vehicle into line with the last
production model of the M3 series, M3A3. In early 1943 the M5A1 replaced
the M5 in production. A small number of both M5 and M5A1 models were
supplied to the British Army who designated both as the Stuart Mk. VI. The
M5 had a turret basket and a gyro-stabilizer for the 37mm gun, and its
general specification matched that of the M3. The M5A1 had a further
improvements including a turret bustle to hold a radio set, a floor escape
hatch, larger access hatches, and improved vision devices.
(From Tamiya Manual) |